support target tripple?

[flihp]

The build process for UEFI applications, or at least the process I've used for this project, is a bit convoluted. This was based on the build process described here: http://www.rodsbooks.com/linux-uefi/. Having to use objdump to transform the shared object to the EFI executable using this method works but ideally we'd be able to use the target triple. I don't know "the right way" to do this though. There's probably a good example out there I just haven't found it. The build system for Grub2 may be a good reference.

[flihp]

Interesting / relevant stuff happening in the clang / rust community:
https://dvdhrm.github.io/2019/01/31/goodbye-gnuefi/
https://github.com/yoppeh/efi-clang